Products    /    Physics Lab Instruments    /    Mechanics    /    Contact Angle Meter

Contact Angle Meter

Model: HO-ED-M-01

Holmarc's Contact Angle Meter (Model No: HO-ED-M-01) is a compact and cost effective CMOS based instrument for measuring contact angles of liquids over substrates. Contact angle is the angle formed by a liquid at the phase boundary where a liquid, gas and solid intersect. The shape of the drop is controlled by the three forces of interfacial tension. The shape of a liquid droplet on a flat horizontal solid surface is determined by the Young-Laplace equation. Image Analysis software is used for measurement and further calculations.

The instrument makes use of a CMOS sensor to form the image of the droplet. The CMOS sensor inputs images and live video to a computer for further analysis.

Manual dispensing syringe pump is used for liquid dispensing. The CMOS sensor and imaging optical assembly are mounted on a translation stage for fine adjustment of image position on the sensor. The dispensing system which consists of a syringe along with linear stage is held on a vertical translator for initial setting of the distance of the needle from the solid surface. Back light is provided by bright LED. The illumination intensity of the back light LED can be controlled.

Experiment Examples

    To measure the contact angle of liquids over various solids.

If H represents the protruding height of droplet and D the diameter of the lens, then the contact angle θ is defined by geometry as,

θ  =  2 arc tan ( 2H / D )

This is the angle formed by a tangent to the droplet at the point the liquid surface meets the supporting block.

    Measuring method
Sessile drop method

    Analysis method
Dropsnake analysis which is based on B-spline snakes (active contours) to shape the drop. Software can be used for measuring contact angles of both symmetrical and asymmetrical drops.

High performance aberration corrected imaging lens with precise manual focus adjustment.

    Video system
High performance CMOS Sensor. 3m shielded USB cable included.

LED based diffused lighting mechanism. Light intensity can be varied.

Mechanical dispenser. 50,100 & 250 micro liter syringes provided with the system.

500 x 400 x 498 mm

    Power supply
230VAC, 50 Hz.

    Other specifications
+/- 180 degree rotation provided for the sample holder. 75mm XY travel provided for the CMOS - optics assembly.
Related Topics

    Thermodynamic equilibrium

    Young - Laplace equation

    Surface tension

Home | Products | Supports | Company | Contact Us


©2020 Holmarc Opto-Mechatronics (P) Ltd. All rights reserved.

Follow us